Means for fighting forest fires



I D. R. M cKAY 2,359,573

MEANS FOR FIGHTING FOREST FIRES Filed March 13, 1-943 INVENTOR 05/71 52A. flQ/M/(A v BY Patented Oct. 3, 1944 UNITED STATES PATENT OFFICE,

MEANS FOR FIGHTING FOREST FIRES I Denver R. MacKay, Buffalo, N. Y.

Application March 13, 1943, Serial No. 479,045

3 Claims.

My invention relates to chemical bombs, and while adapted for varioususes where area distribution of chemical gases for various purposes isdesired it is more particularly adapted for use in combatting fires fromairplanes.

The invention has for its main object the provision of an improved bombto be dropped from airplanes upon fire areas to spread fire' smotheringgases thereover for the purpose of extinguishing the flames. Anotherobject is to provide a bomb of the character referred to which is ofsimple, compact and inexpensive structure, and easily and safelyhandled, and automatic in its operation.

Other objects and advantages of the invention will become apparent fromthe following description of the illustrated embodiment thereof,wherein;

Fig. 1 is an exterior side elevational view of a bomb of the inventionin an inoperative collapsed condition;

Fig. 2 is a similar view but in an operative infiated condition;

Fig. 3 is a sectional view of an element of the invention; and

Fig. 4 is a view showing the preferred application of the invention.

The invention embodies primarily an inflatable and normally collapsedbag I which is formed preferably of flexible material, such as rubber.Integral rib portions II for reinforcing the bag are provided. At oneend of the bag is a neck [2 having an opening I3 leading into theinterior I4 of the bag. Secured in the neck I2 by any suitable meanssuch as the strap I5 is a weighted plug [6 which carries a container IIby means of the support l8 extending interiorly of the bag II).

The invention contemplates the use of chemical solutions such assulphuric acid and bicarbonate of soda solution which when admixed willproduce a fire-extinguishing gas which is heavier than air.

In using the invention to fight a fire which would otherwise be remotefrom adequate fire control facilities, an airplane previously equippedwith bombs of the invention is dispatched to the scene. The bombs may beeither in assembled or unassembled condition, but it is preferred tocarry the bombs in unassembled condition. Thus the plane will beequipped with a supply of the various parts of the bombs to be assembledby an attendant during the flight to the fire area. In assembling thebombs a portion of soda solution is first placed in the bottom of thebag In,

and a portion of the acid solution is placed in the container I1, andthe latter is then snapped onto the support I8 by means of resilientfingers 20 extending from the support. The plug lBis then secured intothe neck l2 of the normally collapsed bag It! by the strap I5, in theposition as shown in Fig. 3, with the opening 2| of the container I!held upwardly to prevent the acid from running out and causing apremature admixture of the chemicals. Any desired number of these bombsmay be so prepared while the plane is on its way to the fire area. Abook 22 is provided in the plug by which the prepared bombs may be hungup in the position as illustrated by Fig. 1 upon any suitable supportmeans, such as a wire 23 carried within the plane 'interior. i

When the plane is approaching the fire area, as illustrated in Fig. 4,the attendant begins throwing the bombs out of the plane. The forces ofgravity acting upon the weighted plug l6 turns the bag over to theattitude shown in Fig. 2, thus releasing the acid solution from thecontainer I! to mix with the soda solution in the bag In, therebygenerating the flame smothering gas which accumulates in the bag,causing it to expand as the gas is generated. The ribs ll' exert arestraining effort upon the expansion of the bag causing the gasto besomewhat compressed. The bombs float down toward the fire area, and uponstriking trees or other sharp objects, or upon contacting the flames ofthe fire the bag becomes ruptured thereby releasing the gas to smotherthe flames. Other general applications of the invention where fire is ahazard, such as in homes, industrial plants, etc., are believed obvious.The prepared bomb may be hung by the hook 22 in any strategic place, andthus if a flre should start the bomb may be readily removed from thesupport and turned over to cause a mixture of the chemicals to form thefire-smothering gas. Then the bomb may be thrown into the flames whichwill rupture the bag and release the gas to smother the fire.

Various adjustments may be made to either retard or speed the generationof gas within the bomb. One method is to vary the size of the opening 2|of the acid container [1. Another method is to vary the quantity ofeither or both of the chemicals. The bag may be made to beself-rupturing by supplying enough chemicals therein to generate gas inexcess of the capacity of the bag, whereby the thinner wall sections ofthe bag between the ribs II will burst under the gas pressure.

Thus the invention provides an improved fire fighting or other gaslaying means, comprising a flexible container which is adapted to bestored in an airplane or the like within a minimum of space prior toarrival at the dispensing point. Upon arrival at the dispensing pointthe container may be simply discharged from the carrying vehiclewhereupon it will automatically assume an inverted attitude resulting inmixing of the gas generating reagents. As the gas generating processproceeds the container expands to accommodate the generated gas, thusassuming a greatly enlarged condition at a time when space consumptionis no detriment, and whereby the generated gas is retained bythe-elastic bag against wasteful dispersion thereof. Upon arrival at theland area over which it is desired to dispense the gas the gas bag is insuch elastically distorted condition as to be adapted to be rupturedwith extreme facility, as in response to slight. contact with any hardobject or in responseto the gas pressure forces which may be arranged toexceed the strength of the bag material. Thus, upon rupturing of the bagthe gas isfinally delivered to the desired land area in the formrof ablanketlof concentrated gas which is adapted to smother the area andtodisplace therefrom the, suppl of air normally surroundingthe same.

. It will also be understood that the bomb of the inventioncan be usedto distribute, chamical warfaregases over battle areas by following theloading and dispensing technique described hereinabove; and, thatalthough the bomb herein illustrated and described ismerely oneembodiment of theinventive principles thereof, the invention may beapplied to other physical embodiments without. departing from the scopeand spirit of theinvention claimed.

I claim:

1. An inflatable aerial bomb for distributing fire smothering gas overfire areas comprising, in combination, a normally collapsed bag havingan opening therein, weightedmeans for sealing said opening, saidweighted means having container. means associated therewith for holdinga gas producing chemical agent, a second chemical agent contained insaid bag separate from said first chemical agent when the bag issupported in upright attitude but which when admixed with said firstchemical agent is adapted to react therewith to produce a heavier thanair fire extinguishing gas for smothering fires, said weighted meansbeing adapted to cause said bag to assume an inverted attitude when saidbag is released in the air to provide admixture of the chemical agentsto produce gas to inflate said bag during descension thereof toward afire area, said bag being adapted to become ruptured upon contact withsolid objects to allow said gas to spread over the fire area to smotherthe fire.

2'. Anaerial'bomb for fighting fires, comprising in combination aflexible inflatable bag adapted to carry a chemical supply therein andhaving a wall portion adapted to rupture upon tearing contact withground objects, a separate openmouthed chamical container supportednormally within said bag for withholding its chemical contents frommixing with thefirst mentioned chemical supply Within said bag, andmeans for causing said bomb to tilt when jettisoned from an aircraft orthe like and to thereby upset said chemical container to provide mixingof said first'and second mentioned chemicals for generation of a fireextinguishing gas.

3. A rubber balloon-like aerial bomb for distributing flame smotheringgas over fire areas, comprising a normally collapsed flexible bagadapted to receive a supply of loose chemical material therein, anopen-mouthed container 1 mounted within said bag for holding a secondchemical normallyseparate from the first mentioned chemical within saidbag when said bag is in an upright attitude, and means associated withsaid bag for causing it to automatically tilt upon being discharged froma moving vehicle or the like and upsetting the chemical contents fromsaid container for mixing thereof with the first mentioned chemical forproducing aflame smothering gas tending to inflate said bag; said bagbeing rupturable when coming into puncturing contact with ground objectsfor releaseofthe flame smothering gas therefrom.

